Basic aluminum antiperspirant active materials having enhanced activity, antiperspirant active compositions containing such materials, and methods for preparation of such materials and compositions

ABSTRACT

Disclosed are basic aluminum antiperspirant materials having univalent complex oxoanions (e.g., nitrate); methods of making such materials; antiperspirant compositions containing such basic aluminum materials, another antiperspirant active material (e.g., a basic zirconium halide salt), and optionally a neutral amino acid: and methods of making such compositions. Size exclusion high performance liquid chromatography chromatograms of the disclosed basic aluminum materials have a peak 4 relative area of at least 25%, a peak 3 relative area of less than 60%, the sum of the peaks 3 and 4 being at least 50%; and less than 10% of the chromatographic peaks eluting at peaks 1 and 2. The disclosed basic aluminum materials have less than 25% of the aluminum in the form of Al b  polyhydroxyaquoaluminum, and have a  27  Al NMR spectrum in which the area of the 71.5-73.5 ppm resonance line includes more than 50% of the combined areas of the 62.5-63.5 ppm and 71.5-73.5 ppm resonance lines, and 5%-30% of the total area under the spectrum from 140 ppm to -80 ppm is contained in the resonance line at 71.5-73.5 ppm. The basic aluminum material of the present invention can be produced by adding a stoichiometric or near-stoichiometric amount of aluminum metal to a solution of an aluminum salt having a univalent complex oxoanion; the basic aluminum material can also be made by adding to such solution of the aluminum salt, aluminum metal having, in total, a relatively small surface area (large-sized particles of aluminum).

This application is a Divisional application of application Ser. No.08/097,620, filed Jul. 27, 1993, abandoned, which is a Continuingapplication of application Ser. No. 07/550,683 filed Jul. 10, 1990,abandoned, which is a Continuation-in-Part application of applicationSer. No. 07/518,516, filed May 2, 1990, U.S. Pat. No. 5,202,115, whichis a Continuation-in-Part application of application Ser. No.07/233,008, filed Aug. 17, 1988, abandoned.

BACKGROUND OF THE INVENTION

The present invention relates to basic aluminum antiperspirant activematerials containing univalent complex oxoanions, antiperspirant activecompositions including such basic aluminum antiperspirant activematerials and also containing another antiperspirant active salt such asa zirconium, hafnium, titanium and/or tin salt, and methods forproducing such materials and compositions. The materials andcompositions of the present invention have a wide range of applicationas antiperspirant materials, including, for example, as antiperspirantactive agents in aerosols, roll-ons, solid sticks, and other knownsystems for delivery of antiperspirant materials to, e.g., the axillaryregion of the human body.

The present invention is particularly directed to basic aluminumantiperspirant materials containing a univalent complex oxoanion ofnitrogen or halogen, antiperspirant compositions containing suchmaterials, and methods of making such materials and such compositions.

In conventional basic aluminum halides, including those having enhancedactivity, aluminum metal has been added in excess to a solution of thealuminum halide salt, since it is known in the art that the formation ofconventional basic aluminum halides requires a level of aluminum metal,to be added to a solution of monomeric aluminum halide, that is inexcess of that required by reaction stoichiometry. According toFitzgerald, "Chemistry of Basic Commercial Aluminum HydrolysisComplexes" in Laden, et al, Antiperspirants and Deodorants (1988), page219, aluminum metal is added in a two--to four--fold excess. If aluminummetal is not added in such excess, aluminum metal will not solubilizerapidly, the aquated aluminum ions will not hydrolyze sufficiently norachieve a sufficiently high level of aggregation, and the desired endproduct will not be formed within a commercially feasible time frame.Aluminum metal may be added in stoichiometric excess in order to ensurea large aluminum metal surface area for more rapid dissolution of therequired amount of metal into water. Once aluminum metal is oxidized byacidic water, the resultant aquated Al³⁺ is available to hydrolyze andform larger hydroxyaquoaluminum aggregates.

The reason for adding such stoichiometric excess of aluminum metal, informing conventional basic aluminum halide materials, can be seen in thefollowing. The reaction stoichiometry for formation of conventionalbasic aluminum halides can be described by the following reactions:

    15H.sub.2 O+5Al+AlX.sub.3 →3Al.sub.2 (OH).sub.5 X+7.5H.sub.2( 1)

    12H.sub.2 O+4Al+2AlX.sub.3 →6Al(OH).sub.2 X+6H.sub.2,(2)

where X is a halide.

It can be seen that in reaction (1), the aluminum metal to aluminumhalide molar ratio is 5:1, and in reaction (2) such molar ratio is 2:1.Reaction equations (1) and (2) represent extremes in commercial basicaluminum halides. As can be seen, the aluminum metal to aluminum halidemolar ratio determines what the end product can theoretically be. Therate of aluminum metal dissolution into water strongly influences whatthe end product actually will be. In each case, in order to ensureformation of the desired end product within a commercially feasible timeframe, the actual aluminum metal to aluminum halide molar ratio usedcommercially is larger than that required by the reaction stoichiometryrepresented by the above reaction equations. Typically, this molar ratioof actual aluminum metal to aluminum halide, in commercial systems, willvary between 3:1 and 10:1.

As can be seen in the foregoing, the important feature in formingconventional basic aluminum halide material is to achieve rapidsolubilization of the aluminum metal (as discussed in the above, forexample, by adding a level of aluminum metal in excess of that requiredby reaction stoichiometry). Larger aluminum metal surface areas, forexample, by use of aluminum powders, would also permit achievement ofrelatively rapid solubilization of the aluminum. Thus, for example, useof aluminum powders would permit use of lower molar ratios.Unfortunately, aluminum metal powder is hazardous to handle, and can beexplosive if proper precautions are not taken.

U.S. patent application Ser. No. 07/518,516, filed May 2, 1990, now U.S.Pat. No. 5,202,115, issued Apr. 13, 1993 which is a continuation-in-partapplication of U.S. patent application Ser. No. 07/233,008, filed Aug.17, 1988 (the contents of the continuation-in-part application and thecontents of No. 07/233,008 each being incorporated herein in theirentirety), discloses basic aluminum antiperspirant active materials(polymeric aluminum materials) having the empirical formula: Al₂(OH)_(6-a) X_(a), where 0.5≦a ≦5.0, and X is a univalent complexoxoanion of nitrogen or halogen, such as NO₃ ⁻, ClO₃ ⁻, ClO₄ ⁻ and IO₄⁻, the antiperspirant active material being further characterized by:

(a) Size exclusion high performance liquid chromatography (HPLC) peakscorresponding to peak 3 and peak 4 of the size exclusion chromatogramproduced from a high performance liquid chromatography technique;

(b) A peak 4 relative area of at least 25%, and a peak 3 relative areaof less than 60%, the sum of the relative peak 3 and peak 4 areas beingat least 50%; and

(c) Less than 10% chromatographic peaks eluting at shorter retentiontimes (or larger molecular sizes) than the peak 3, corresponding topeaks 1 and 2.

This continuation-in-part application discloses that the basic aluminummaterials described therein can be produced at relatively lowtemperatures, such as at temperatures below 45° C., with the time ofheating in the temperature range of 45° C-140° C. being 0.5-17 hours.This continuation-in-part application discloses that the basic aluminummaterials described therein can be formed at lower temperatures, and/orin smaller amounts of time, and at higher initial aluminum solutionconcentrations, than when using techniques for forming conventionalbasic aluminum halide materials having enhanced antiperspirant activity.

This continuation-in-part application discloses that the described basicaluminum material can be formed by dissolving an aluminum salt of theunivalent complex oxoanion in water, heating, and (while heating) adding.additional aluminum in metallic form. Where the aluminum salt is analuminum nitrate, the reaction scheme for forming the basic aluminummaterial in the foregoing continuation-in-part application is describedas follows:

    58H.sub.2 O+28Al+16Al(NO.sub.3).sub.3 →22Al.sub.2 (OH).sub.5 NO.sub.3 +26NO+3H.sub.2,

where the production of nitric oxide represents a reduction of thenitrate oxoanion from a formal +7 to +2 oxidation state on the nitrogenatom. This continuation-in-part application also discloses that thealuminum salt of the univalent complex oxoanion can be formed in situ,by reacting aluminum metal with, e.g., an inorganic acid of theunivalent complex oxoanion.

Consistent with techniques in connection with conventional basicaluminum halide materials, this continuation-in-part applicationdescribes forming the described basic aluminum material having theunivalent complex oxoanion by adding small turnings of aluminum metal inthe form of oblong pieces 1/16 inch to 1/8 inch long and 1/100 inch to3/100 inch thick, in excess, to a solution of monomeric aluminum ion andunivalent complex oxoanion.

This continuation-in-part application also discloses a basic aluminumantiperspirant material having enhanced efficacy, wherein such materialcontains at least 25% by weight of the aluminum in the form of Al^(b)polyhydroxyaquoaluminum. This continuation-in-part application disclosesthat, typically, the antiperspirant active material contains up to 50%by weight of the total aluminum in the form of Al^(b)polyhydroxyaquoaluminum.

While the continuation-in-part application, and application Ser. No.07/233,008, describe basic aluminum antiperspirant materials containingunivalent complex oxoanions, having enhanced antiperspirant activity,which can be provided directly (that is, without previously forming abasic aluminum material and then heating) at relatively low temperaturesand which are relatively stable, it is still desired to provide basicaluminum materials having improved antiperspirant activity and which canbe provided utilizing a relatively safe and inexpensive technique, in arelatively short period of time.

U.K. Patent Application No. 2,048,229 describes a group of complexes(Al^(c')) within the aluminum chlorhydroxides which are more efficaciousas an antiperspirant. Such group Al^(c') complexes with a ferron reagentat a reaction rate characteristic of Al^(c) (of Al^(a), Al^(b) andAl^(c), Al^(c) is the group that exhibits the slowest complexingreaction ratio with ferron), and has a permeation rate in gel permeationchromatography which is within that ;range generally found for Al^(b)(of Al^(a), Al^(b) and Al^(c), Al^(b) has an intermediate retentiontime, indicating it includes complexes of intermediate molecular size).This U.K. patent application describes that the Al^(c') group ofcomplexes was present in amounts of 10%-30% by weight in then-availablealuminum chlorhydroxides, and that these then-available aluminumchlorhydroxides can be modified to contain substantially larger amountsof the Al^(c') group. This patent application discloses a technique toincrease the amount of the Al^(c') group, by aging then available(commercial) aluminum chlorhydroxide.

This U.K. Patent Application does not disclose use of basic aluminummaterials having a univalent complex oxoanion of nitrogen or a halogen,does not describe direct preparation of the basic aluminum material(rather, disclosing aging of then available aluminum chlorhydroxide),and does not achieve the advantages of the present invention.

European Patent Application No. 191,628, the contents of which areincorporated herein by reference in their entirety, discloses a directprocess of making a basic aluminum halide in powder form having analuminum:halogen molar ratio of from 1.7 to 2.2:1 and having at least20% of the aluminum contained in a Band III fraction. This processincludes steps of:

(a) dissolving metallic aluminum in an aqueous starting solution of analuminum compound selected from aluminum chloride and aluminum bromide,the starting solution being held at a temperature of about 50° C. toabout 105° C., for a time just long enough to dissolve sufficientaluminum to produce an aqueous solution of a final basic aluminum halidehaving an aluminum:halide molar ratio in the range 1.7:1 to 2.2:1, theconcentration of the aluminum in the starting solution and the amount ofaluminum dissolved being such that the aluminum concentration in thesolution of the final basic aluminum halide is from 0.8% to 6.75% byweight, and the final basic aluminum halide having at least 20% of thealuminum contained in the Band III fraction; and

(b) drying the solution of the final basic aluminum halide so as to givethe final basic aluminum halide in the form of a hydrated powder havingat least 20% of the aluminum contained in the Band III fraction.

European Patent Application No. 191,628 further discloses that in thedirect preparative procedure for forming the described basic aluminumhalide material, under some conditions products containing a highproportion of the aluminum in the Band III species contain a substantialproportion of this component in the form of a polymer having acharacteristic line in the ²⁷ Al NMR (nuclear magnetic resonance)spectrum. This patent application discloses this characteristic line is62.5 ppm downfield from the resonance of Al³⁺ (6H₂ O), and has beenattributed to a complex aluminum ion referred to as the Al₁₃ O₄₀ ion. Inone embodiment of the disclosed process, at least 20% of the aluminum ofthe final basic aluminum compound is in the form of the Al₁₃ O₄₀ ion.

European Patent Application No. 285,282 discloses antiperspirantmaterials, including partially neutralized aluminum salts, the saltshaving at least 25% of the total aluminum present in a form having a ²⁷Al NMR spectrum wherein 8% to 25% of the total area under the spectrumfrom 140 ppm to -80 ppm is contained in a peak at approximately 63 ppm(corresponding to tetrahedrally co-ordinated aluminum ions). ThisEuropean patent document discloses a technique for forming the describedaluminum salt, by partially neutralizing an aqueous acid (such as amineral acid) using a source of aluminate ion (the mineral acidoptionally being an aluminum salt), with no subsequent heating steprequired. Specifically embodied in this patent document are aluminumhalohydrate materials, such as aluminum chlorhydrate; the disclosedaluminum chlorhydrate has an increased proportion of smaller species andis deficient in the larger polymeric species.

While each of European Patent Application No. 191,628 and No. 285,282describe direct techniques for forming a basic aluminum antiperspirantmaterial, each of these patent documents are primarily directed tohalide materials. Moreover, European Patent Application No. 285,282discloses halide and nitrate materials formed by reacting an aluminatewith, e.g., an aluminum salt, rather than use of aluminum metal to reactwith an aluminum salt. Neither of these European patent applicationsdisclose basic aluminum compounds as in the present invention, havingenhanced antiperspirant activity, which can be manufactured by arelatively safe and inexpensive technique.

It is also desired to provide an antiperspirant composition including abasic aluminum material containing a univalent complex oxoanion andanother antiperspirant active material, and a method of producing suchcomposition.

The aforementioned continuation-in-part U.S. patent application, filedMay 2, 1990, and its parent application Ser. No. 07/233,008, filed Aug.17, 1988 (the contents of each of which have previously beenincorporated herein by reference in their entirety) discloseincorporating the described basic aluminum antiperspirant material withenhanced antiperspirant activity, having a univalent complex oxoanion,in a composition including another antiperspirant active compound (forexample, a compound containing a metal cation selected from Zr, Hf, Tior Sn), such composition containing (or not containing) a neutral aminoacid. The patent applications disclose that the composition can beprepared by simple mixing of a solution of the basic aluminum materialhaving enhanced antiperspirant activity with a solution of the Zr, Hf,Ti and/or Sn material (for example, a solution of zirconylhydroxychloride), the temperature of such mixing being at least roomtemperature, and, illustratively, at a temperature of 45°-140° C. Thepatent applications disclose that the composition can be providedwithout dilution and/or heating, and thus is more stable in water ascompared to corresponding compositions using aluminum chlorhydrate ofenhanced antiperspirant activity.

U.S. Pat. No. 2,814,585 to Daley discloses an antiperspirant compositionincluding in combination an aqueous solution of a zirconium or hafniumsalt of a strong monobasic mineral acid, a basic aluminum compound, andan amino acid in which the number of amino groups is .equal to thenumber of carboxyl groups in the molecule (that is, neutral aminoacids). This patent discloses that the basic aluminum compounds and theamino acids act as buffering agents to bring the pH of the solution ofthe zirconium or hafnium salt to a value which renders it safe forantiperspirant usage. This patent discloses that the basic aluminumcompounds with which the hafnium and zirconium salts, and neutral aminoacids, are combined have the general empirical formula Al₂ (OH)_(6-n)X_(n), where X is a monovalent acid anion of the group Cl⁻, Br⁻, I⁻ andNO₃ ⁻, and n has an average value from about 0.8 to about 2.

U.S. Pat. No. 4,331,609 to Orr discloses antiperspirant compositionswhich are non-irritating to the skin and which are non-damaging totextiles, the compositions including an aluminum compound, a zirconiumcompound, a neutral amino acid and an inorganic acidic compound. Thispatent discloses that the aluminum compound has the empirical formulaAl₂ (OH)_(6-n) X_(n), wherein n has a value of from about 0.80 to about1.25 and X is selected from the group consisting of chlorine, bromine,iodine, sulfamate, sulfate, nitrate and mixtures thereof.

While each of U.S. Pat. No. 2,814,585 and 4,331,609 discloseantiperspirant compositions including a basic aluminum compoundcontaining a univalent complex oxoanion (e.g., nitrate), neither ofthese patents disclose that the basic aluminum nitrate is a nitratehaving enhanced antiperspirant activity, much less compounds havingspecific NMR spectra and/or form. Moreover, these patents do notdisclose achieving further enhanced activity, based on specifictechniques for forming the compounds. In addition, these patents teachthat the nitrates therein are equivalent to, e.g., the chlorides.

U.S. Pat. No. 4,775,528 to Callaghan, et al discloses an antiperspirantcomposition having high antiperspirant efficacy, comprising zirconylhydroxychloride and aluminum chlorhydroxide in which the atomic ratio ofAl to Zr is from 6:1 to 1:1, such composition (when dissolved in waterto form a 10% by weight solution and, after storage at room temperaturefor no more than two hours, subjected to gel permeation chromatographyon cross-linked dextran having a molecular weight exclusion range of1,000 to 30,000 for globular proteins (Sephadex G-50)) exhibiting adistribution pattern having peaks at Kd=0.7 and Kd=0.5 in which theratio of the height of the first peak to that of the second is at least1.5:1. This patent also discloses a method of making such composition,wherein a 2%-18% solution of aluminum chlorhydroxide in water is heatedat a temperature of at least 50° C. with the zirconyl hydroxychloridebeing mixed therewith before, during or after the heating step, theamount of the zirconyl compound being sufficient to provide an atomicratio of Al:Zr from 6:1 to 1:1, the heating being continued until theabove-referred-to distribution pattern is achieved. This patent furtherdiscloses that the composition can optionally also include a neutralamino acid. With reference to FIG. 1 of U.S. Pat. No. 4,775,528, thispatent teaches that peak 1 of the chromatogram of the composition (peak1 being the first eluted fraction) contains the zirconium compound; thatpeak 2 contains the Al^(c) complex; that peak 3, at Kd=0.5, contains theAl^(c') complex; and that peak 4, at Kd=0.7, which appears only as ashoulder between peaks 3 and 5, contains a hitherto unrecognized novelcomplex which is present only in a small proportion, while peaks 5 and 6are fractions containing Al^(a) or other lower molecular weightcompounds.

This patent does not teach or suggest compositions including basicaluminum materials, having enhanced antiperspirant activity, containingunivalent complex oxoanions, as in the present invention. Moreover, thispatent does not teach or suggest the amount of the basic aluminumcompound in the form of Al^(b), or the ²⁷ Al NMR spectrum, as in thepresent invention.

U.S. Pat. No. 4,606,915 to Rosenberg, et al discloses that a compositionof a stannic halide and an aluminum halohydrate, and also preferablycontaining a neutral amino acid, is useful in inhibiting perspirationwhen applied to the skin of a subject in powder form or whenincorporated in a liquid or solid vehicle. In this patent, there is nodisclosure that the aluminum compound has enhanced activity, nor thatthe resultant basic tin/aluminum halohydrate demonstrates enhancedantiperspirant activity. The contents of U.S. Pat. No. 4,606,915 areincorporated herein by reference in their entirety.

Accordingly, it is still desired to provide basic aluminum materialswith further enhanced antiperspirant activity; and compositions of (1)zirconium, hafnium, tin and/or titanium active antiperspirant material,either those conventionally known or those having enhancedantiperspirant activity, with (2) basic aluminum material having furtherenhanced antiperspirant activity, which materials and compositions canbe made inexpensively and safely, and which are stable after beingformed. It is also desired to make such basic aluminum materials andsuch compositions, without the necessity of using high temperaturesand/or high pressures, and without the need for extra manufacturingsteps of heating diluted solutions of already manufactured basicaluminum compounds. It is also desired to provide such materials andcompositions in concentrated aqueous solutions.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide basicaluminum antiperspirant active materials (containing, e.g., univalentcomplex oxoanions) having further enhanced antiperspirant activity,which can be produced relatively cheaply and safely (for example, withsubstantially decreased danger of explosion), and to provide methods ofmaking such materials.

It is another object of the present invention to provide antiperspirantcompositions containing (1) such basic aluminum antiperspirant activematerials having further enhanced antiperspirant activity, and (2) atleast another antiperspirant active material such as anotherantiperspirant active salt, and methods of making such compositions.

It is a further object of the present invention to provide such basicaluminum materials, which can be produced at relatively low temperaturesand fast rates, with a higher initial aluminum concentration in thesolution.

It is a still further object of the present invention to provide suchbasic aluminum antiperspirant active materials with further enhancedactivity, and methods of forming such materials, wherein the materialscan be provided without the need for extra manufacturing steps ofheating diluted solutions of already manufactured basic aluminummaterials at high temperature and/or pressure conditions.

It is a still further object of the present invention to provide suchbasic aluminum antiperspirant materials having further enhancedantiperspirant activity, which has improved stability in aqueoussolution over extended periods of time.

It is a still further object of the present invention to provideantiperspirant compositions having further enhanced antiperspirantactivity, the compositions including basic aluminum antiperspirantmaterials having further enhanced antiperspirant activity together withanother antiperspirant active material, which has improved stability inaqueous solution and which can be produced at lower temperatures, andmethods of producing such compositions.

The present invention achieves each of the above objectives with basicaluminum materials (polymeric aluminum materials) having the empiricalformula:

    Al.sub.2 (OH).sub.6-a X.sub.a,

where 0.5≦a≦5.0, X is an anion as discussed further infra, and whereinthe antiperspirant active material is further characterized by:

(a) size exclusion high performance liquid chromatography peakscorresponding to peak 3 and peak 4 of the size exclusion chromatogramproduced from a high performance liquid chromatography (HPLC) technique,discussed further infra:

(b) a peak 4 relative area of at least 25%, and a peak 3 relative areaof less than 60%, the sum of the relative peak 3 and peak 4 areas beingat least 50%;

(c) less than 10% chromatographic peaks eluting at shorter retentiontimes (or larger molecular sizes) than peak 3, corresponding to peaks 1and 2;

(d) less than 25% of the aluminum being in the form of Al^(b)polyhydroxyaquoaluminum;

(e) an ²⁷ Al NMR (nuclear magnetic resonance) spectrum wherein 5%-30%,preferably 8%-18%, of the total area under the spectrum from 140 ppm to-80 ppm is contained in a resonance line at 71.5-73.5 ppm; and

(f) an ²⁷ Al NMR spectrum in which the area of the 71.5-73.5 ppmresonance line includes more than 50% of the combined areas of the62.5-63.5 ppm and 71.5-73.5 ppm resonance lines.

The anions (X) of the above-stated empirical formula, within the scopeof the present invention, are univalent complex oxoanions of nitrogen,chlorine and other halogens, including, but not limited to, NO₃ ⁻, ClO₃⁻, ClO₄ ⁻ and IO₄ ⁻, which form salts with Al³⁺ in aqueous solution, sothat these salts are essentially completely dissociated, which anionsare readily soluble in water with metallic ions in the solution (forexample, Al ions; or, where the solution contains other antiperspirantactive materials such as Zr, Hf, Ti and/or Sn antiperspirant activematerials, Al ions and the metallic ions of the other antiperspirantmaterials), and which form conjugate acids that are strong acids. Bystrong acid, we mean those acids having the ability to substantiallycompletely dissociate H⁺ (e.g., at least 98% dissociated) in aqueoussolution. Furthermore, those anions within the scope of the presentinvention are labile with respect to undergoing reduction, the productsof the reduction being gases or soluble anions of lower oxidation statesof nitrogen or halogen than in the starting anion (the starting anion isthe anion of the Al salt used to form the basic aluminum material of thepresent invention, as discussed further infra). A preferred anion is thenitrate anion (NO₃ ⁻).

Various anions which can be utilized as part of the present inventionhave been set forth above, as well as functional characteristics ofusable anions in general. Sulfate and phosphate anions (and similaranions) will not work as part of the present invention, because theycomplex to too great an extent with aluminum.

The basic aluminum materials of the present invention have substantiallyno species with a size greater than 100Å. Furthermore, the pH of thebasic aluminum materials within the scope of the present invention ishigher than that of the corresponding basic aluminum halide material;thus, materials within the scope of the present invention are gentler onthe skin of axillary areas, as compared to the corresponding basicaluminum halide materials.

Preferred relative areas for peak 3 and peak 4 of the basic aluminummaterial are a peak 4 area of at least 35% but less than 80% and a peak3 area of less than 50%, the sum of the peak 3 and peak 4 areas being atleast 60% but less than 90%; moreover, it is also preferred that thebasic aluminum material include essentially no peaks 1 and 2.

The foregoing objectives can also be achieved by the process of thepresent invention, wherein aluminum metal is added to a solution of analuminum salt in such a manner as to achieve a low aluminum metalsurface area, rather than to achieve a large metal surface area as isnecessary in forming basic aluminum halides of the prior art.

Methods of forming the basic aluminum materials of the present inventioninvolve dissolving an aluminum salt of the aforementioned univalentcomplex oxoanions in water, heating, and (while heating) addingadditional aluminum in the metallic form. In general, the reaction canbe written as follows:

    H.sub.2 O+Al+Al(Y.sup.w O.sub.n).sub.3 →Al.sub.2 (OH).sub.6-a (Y.sup.z O.sub.n).sub.a +H.sub.2 +(Y.sub.p.sup.v O.sub.h).sup.f,

where a is as defined previously, Y^(z) O_(n) is a univalent complexoxoanion of nitrogen or halogen described previously as X, p is 1 or 2,0≦h≦5, w is the oxidation state of nitrogen or halogen, n is dependentupon the oxidation state of Y, f is 0 or --1, 0≦v<w and 0<z≦w. Therelationship between w and v represents an overall reduction of the Yatom resulting in a lower oxidation state for that atom in the Y_(p)^(v) O_(h) by-product than in the original Al(Y^(w) O_(n))₃. As is clearfrom the foregoing reaction scheme, the anion of the aluminum saltreactant is labile with respect to undergoing reduction. Moreover, asindicated previously, the product of the reduction (Y_(p) ^(v) O_(h)) isa gas or soluble substance.

In the foregoing reaction scheme, the Al is added, according to thepresent invention, to achieve a low aluminum metal surface area. Addingthe aluminum metal to the solution of the aluminum salt, the aluminummetal dissolves rapidly in water, the aquated aluminum ion hydrolyzessufficiently and achieves a sufficiently high level of aggregation, andthe reaction easily and quickly goes to completion in a commerciallyfeasible time frame.

Furthermore, lowering the aluminum metal surface area allows greatercontrol over the course and extent of the oxidation-reduction-hydrolysisreaction. That is, using the method of the present invention it iseasier to isolate a basic aluminum material with any desireddistribution of polyhydroxyaquoaluminum polymer sizes according to sizeexclusion HPLC.

Another advantage of the present methods for forming the basic aluminummaterials according to the present invention, utilizing aluminum metalso as to achieve a low aluminum metal surface area, is the fact that itis unnecessary to use hazardous powdered aluminum metal (for providing alarge metal surface area as is necessary in basic aluminum halides ofthe prior art) in order to achieve lower aluminum metal molar ratiosand/or faster reaction rates.

Thus, according to the present methods, the aluminum is added in such amanner as to achieve a low aluminum metal surface area, such that theresultant basic aluminum material contains significantly less aluminumin the form of Al^(b) polyhydroxyaquoaluminum, less aluminum in the formof polymers characterized by an ²⁷ Al NMR resonance line at 62.5-63.5ppm, and significantly more aluminum in the form of polymerscharacterized by a ²⁷ Al NMR resonance line at 71.5-73.5 ppm thanobtained when aluminum metal is added in such a way as to ensure a largemetal surface area.

As another way of defining a preferred aspect of the methods accordingto the present invention, aluminum metal is added to a solution of thealuminum salt so as to achieve a low aluminum metal surface area suchthat the formed basic aluminum material has less than 25% of thealuminum in the form of Al^(b) polyhydroxyaquoaluminum and has a ²⁷ AlNMR spectrum in which the area of the 71.5-73.5 ppm resonance linecomprises more than 50% of the combined areas of the 62.5-63.5 ppm and71.5-73.5 ppm resonance lines.

Desirably, the formed basic aluminum materials have an ²⁷ Al NMRspectrum wherein 5%-30%, preferably 8%-18%, of the total area under thespectrum from 140 ppm to -80 ppm is contained in a resonance line at71.5-73.5 ppm.

In the foregoing description concerning the methods of forming the basicaluminum material, it is described that the aluminum salt of theunivalent complex oxoanion (Al(Y^(w) O_(n))₃) is dissolved in water,with additional aluminum being added (while heating). However, theformation of the basic aluminum material of the present invention can bepracticed by the preparation of the aluminum salt of the univalentcomplex oxoanion in situ, by mixing aluminum metal with an inorganicacid, HY^(w) O_(n) ; permitting the aluminum metal to dissolve (heatingis usually necessary, typically between 45°-140° C.); and thencontinuing the reaction by addition of more aluminum metal to the formedAl(Y^(w) O_(n))₃ as discussed in the foregoing. The aluminum metal mixedwith the inorganic acid may be of large or small surface area. The acidutilized in the in situ formation of Al(Y^(w) O_(n))₃ can beillustratively (but not limitingly), HNO₃, HClO₄, HClO₃ and HIO₄. Informing the nitrate, HNO₃ is used.

The present invention also includes incorporating the basic aluminumantiperspirant materials as described above, having the recited Al^(b)polyhydroxyaquoaluminum amount and ²⁷ Al NMR spectrum, with anotherantiperspirant active material (e.g., an antiperspirant active salt ofZr, Hf, Ti or Sn), and with or without a neutral amino acid, to formantiperspirant compositions. Specifically, the antiperspirantcompositions can be the following:

    [Al.sub.2 (OH).sub.6-a (X).sub.a ].sub.w [DO.sub.p (OH).sub.m Q.sub.n ].sub.y [neutral amine acid).sub.z

where a and X are as defined previously, w:y ranges from about 0.3:1 toabout 6.0:1, z:y ranges from 0 to 1.3:1 and p is either 0.0 or 1.0. Whenp=0, then m=0 and n=4; when p=1, then m+n=2. While not limiting, Dillustratively is a metal cation selected from Zr, Hf, Ti or Sn; and Qis a halide, such as Cl, NO₃ or any of the univalent complex oxoanionsfurther described herein. Generally, the compound containing the metalcation selected from Zr, Hf, Ti or Sn includes those known as activeantiperspirant materials, and which are compatible with the basicaluminum material of the present invention. The preferred neutral aminoacid is glycine, but may be alanine, phenylalanine or other knownneutral amino acids.

The compositions according to the present invention have a peak 4relative area of at least 25%, and a peak 3 relative area of less than50%, the sum of the peak 3 and peak 4 areas being at least 40%. Unlikethe basic aluminum antiperspirant material, the active composition ofthe present invention, containing a zirconium compound component, forexample, may contain significantly more than 10% chromatographic peakseluting at shorter retention times than peak 3, corresponding to peak 1and not peak 2, said composition having less than 10% chromatographicpeaks corresponding to peak 2. For example, the zirconium compoundcomponent could contribute more than 10% peak 1 to the activecomposition. The active composition of the present invention may containup to 35% chromatographic peak 1 corresponding to the zirconium compoundcomponent of the composition.

The compositions can be prepared by simple mixing of a solution of thebasic aluminum material having the enhanced antiperspirant activity,with a solution of the metal cation compound (for example, a solution ofzirconyl hydroxychloride). The temperature of such mixing can be atleast room temperature, for example, at room temperature. The mixing canbe at temperatures above room temperatures, for example, at temperaturesof 45° C.-140° C.

The basic aluminum antiperspirant materials of the present invention,and the compositions of the present invention including such basicaluminum materials, can be obtained in powdered form from an aqueoussolution by spray-drying or freeze-drying, for example. The conversionof the aqueous antiperspirant solution to a dried (for example,spray-dried) antiperspirant powder can be accomplished by any one ofmany techniques known to those skilled in the art, and these techniquesare more or less suitable for commercial use.

As another aspect of the present invention, the aluminum metal should beadded in stoichiometric or near-stoichiometric amounts to a solution ofAl(Y^(w) O_(n))₃, where Y, w and n are defined as set forth previously,rather than in excess as in prior techniques. Using such stoichiometricor near-stoichiometric amounts of aluminum, the reaction easily andquickly goes to completion, the aluminum hydrolyzing sufficiently andachieving a sufficiently high level of aggregation. Moreover, when thealuminum metal is added in stoichiometric amounts, the resultant basicaluminum material contains significantly less Al^(b)polyhydroxyaquoaluminum and less aluminum in the form of polymerscharacterized by a ²⁷ Al NMR resonance line at 62.5-63.5 ppm thanobtained when aluminum metal is added in large excess.

As a further aspect of the basic aluminum materials of the presentinvention is basic aluminum materials (polymeric aluminum materials)having the empirical formula:

    Al.sub.2 (OH).sub.6-a X.sub.a,

where a and X are as defined previously, with the antiperspirant activematerial being further characterized by:

(a) a size exclusion HPLC chromatogram which contains:

(1) a peak 4 relative area of at least 40%, a peak 3 relative area ofless than 30%, the slim of the relative peak 3 and peak 4 areas being atleast 50%;

(2) a combined peak 5 and 6 relative area of at least 15%; and

(3) less than 10% chromatographic peaks eluting at shorter retentiontimes than peak 3, corresponding to peaks 1 and 2;

(b) a ²⁷ Al NMR spectrum in which:

(1) a 71.5-73.5 ppm resonance line comprises at least 5% of the totalarea of the NMR spectrum, and desirably can comprise as much as 30% ofthe total area;

(2) a 0-5 ppm resonance: line comprises at least 5% of the total NMRarea, and desirably can comprise as much as 30% of the total area; and

(3) a 62.5-63.5 ppm resonance line comprises less than 10% of the totalarea of the NMR spectrum; and

(c) less than 25% of the total aluminum in the form of Al^(b)polyhydroxyaquoaluminum.

As another aspect of the present invention, the basic aluminum materialsdescribed above, which can be formed by adding the aluminum metal instoichiometric amounts, can be reacted for an additional period of timesufficient to maximize the HPLC peak 4 relative area of the basicaluminum materials to at least 60%, while maintaining a peak 3 relativearea of less than 25%, with the sum of peak 3 and peak 4 being at least70%, and the combined peak 5 and peak 6 area being less than 20%. Thisaspect of the basic aluminum material is further characterized by an ²⁷Al NMR spectrum 0-5 ppm resonance line of less than 10% of the totalarea. Other characteristics of this aspect of the present invention (theamounts of peaks corresponding to peaks 1 and 2, the 71.5-73.5 and62.5-63.5 ppm resonance lines, and the Al^(b) polyhydroxyaquoaluminum)are the same as set forth in the immediately preceding paragraph.

Accordingly, the present invention achieves antiperspirant activematerials, and compositions containing such active materials, havingenhanced antiperspirant activity that is even further enhanced than theantiperspirant activity of the compounds and compositions described inU.S. patent application Ser. No. 233,008, and the continuation-in-partapplication thereof. Moreover, the present materials and compositionscan be provided using relatively large pieces of aluminum, avoiding anypossibility of hazards of explosion due to use of, e.g., aluminum metalpowder. Furthermore, through use of near-stoichiometric amounts ofaluminum, excess use of aluminum can be avoided so that costs due tosuch excess aluminum can be avoided. In addition, the present inventionalso achieves all advantages achieved by the material and compositiondescribed in U.S. patent application No. 233,008, and thecontinuation-in-part application thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-3, respectively, are high performance liquid chromatography sizeexclusion chromatograms for the products of Examples 1-3.

FIGS. 4-6 are ²⁷ Al nuclear magnetic resonance (NMR) diagrams for theproducts of Examples 1-3, respectively.

FIGS. 7-9 are high performance liquid chromatography size exclusionchromatograms for the product of Example 4, at specified times afteraddition of aluminum metal to the solution of the aluminum salt.

FIG. 10 is a high performance liquid chromatography size exclusionchromatogram for the product of Comparative Example 1.

FIG. 11 is a ²⁷ Al NMR diagram for the product of Comparative Example 1.

DETAILED DESCRIPTION OF THE INVENTION

While the invention will be described in connection with specific andpreferred embodiments, it will be understood that it is not intended tolimit the invention to those embodiments. On the contrary, it isintended to cover all alterations, modifications and equivalents as maybe included within the spirit and scope of the invention as defined bythe appended claims.

Prior to the detailed description of the present invention, theanalytical chromatographic, ferron complexation and ²⁷ Al NMR proceduresfor determining various values in connection with the present inventionwill be described.

The analytical chromatographic procedure is performed using pre-packagedBondagel silica-based columns available from Waters Associates in 3.9 mm(ID) by 30 cm steel columns. A combination of Bondagel E-125 and/orPorosil GPC 60 A columns connected in series is used. The column mobilephase is 0.01M nitric acid. The mobile phase is pumped through thecolumns at a 0.5 ml/minute flow rate using a high performance liquidchromatography pump system (e.g., Waters model 501 or 510). A refractiveindex detector (e.g., Waters model 401 or 410) is used to detect samplefractions as they are eluted from the columns. The detector is linked toa printer or plotter to provide a chromatogram and to an integratorwhich measures the elution times or volumes of the fractions and therelative chromatographic peak areas. The Waters model 730 Data Module isan example of a printer, plotter integrator. Many computerized systemsare also available. Microliter quantities of the aqueous antiperspirantsolutions of interest are injected into the column system with amicro-syringe using an injector system such as the Waters model U6K.

Those skilled in the art will obtain size exclusion high performanceliquid chromatograms which resemble those provided in the figures byjudicious selection of column types, length of columns, flow rates,recorder/integrator type and sensitivity, detector type and sensitivity.Furthermore, those skilled in the art will be able to make peakassignments, relative to appropriate standards, so that peak 3 and peak4 will be easily distinguishable from other peaks of shorter and longerrelative retention times.

To elaborate, peak 3 and peak 4 always elute in sequential order, thatis, peak 3 is prior to arid distinguishable from the subsequent peak 4(peak 3 elutes at shorter retention times than peak 4). These peaks fallwithin a HPLC peak series which elute in order of decreasing apparentmolecular volume. The earliest peak, designated as peak 1, representingthe highest molecular volume, may not contain aluminum and may only bepresent in polymeric species of the antiperspirant composition and notthe antiperspirant material of the present invention. Peaks 2-8 arepresent in both mixed metal systems (e.g., aluminum/zirconium) and innon-mixed metal systems containing only aluminum. Peak 8 is due to thetotally included species (limit of column interstitial volume) mostlikely due to inorganic acid. Relative retention times have beencalculated for each of the chromatographic peaks as the ratio of theirretention times to the retention time of this totally included group ofmolecular species. Average values of 0.61 for peak 3 (0.59-0.64) and0.69 for peak 4 (0.64-0.75) have been found. The exact retention times(or relative retention times) of each peak can be reproduced accurately.However, comparison to a standard basic aluminum polymer solution HPLCsize exclusion chromatogram alleviates any problems caused by flow ratedeviations, column bed degradation or sample preparation adjustments(concentration, injection volume, etc.)

Peak areas as reported are calculated by a chromatographic algorithmwhich integrates the area under each peak from its start to finish asthe peak boundaries touch a horizontal baseline as a reference point. Ifresolution of two adjacent peaks is inadequate, a perpendicular linefrom the lowest point of the valley between them is dropped to thehorizontal baseline to designate the endpoint of the prior peak and thestarting point of the subsequent peak. These areas are thenmathematically totalled and the percentage of each peak area relative tothe total chromatographic peak areas is reported.

The reaction is monitored by removing aliquots of reaction medium every0.5 hour. The heating is discontinued once the HPLC profile correspondsto the previously mentioned peak parameters. This is followed byfiltering off the excess aluminum, and, if a solid or powder form isdesired, by spray-drying of the solution.

The ferron complexation reaction procedure is performed by following thereaction of the ferron reagent (L) with the polyhydroxyaquoaluminumspecies. The absorbance at 368 nm of the aluminum ion-ferron reagentcomplex (ALL₃) was monitored over time relative to that of the freeligand (L). The liquid solution was prepared by the addition of 5 ml ofa 5.7×10⁻³ molar ferron solution, 2 milliliters; of a 1.4 molarhydroxylamine hydrochloride/0.48 molar hydrochloric acid solution, and 2milliliters of a 2.6 molar sodium acetate solution to 25 milliliters ofdeionized water. The amine/weak acid salt combination buffers thesolution at pH 5. To this, 2 milliliters of a 0.02% (w/w) aluminumsample (approximately 1.5×10⁻³ molar Al) is added and the absorbance ofthe analyte solution is recorded within three minutes and every 30minutes thereafter up to 6 hours. Daily readings were taken up to 10days. The absorbance due to the AlL₃ complex was determined at each timeperiod and sequential absorbance differences between absorbance valuesat 3 minutes, 6 hours and 10 days provided the Al^(a) (low molecularweight), Al^(b) (intermediate oligomeric size) and Al^(c) (largerpolymeric species) distribution in aqueous solution.

The ²⁷ Al NMR technique and the method of calculating the ²⁷ Al NMRresonance line areas are as follows: ²⁷ Al NMR data were collected oneither a SDS 360-1 (v_(L) =94.676MHz) or a SDS 360-2 (v_(L) =93.788MHz)instrument. Data were collected from approximately +160 to -100 ppm,using a 90° pulse (or less, if the signal was saturating the receiverelectronics) and a recycle delay of 250 ms. This optional length of therecycle delay was determined from a simple progressive saturationexperiment. Sample concentrations were 10% w/w (about 400 mg/4 gm D₂ Osolution). 10 mm quartz NMR tubes (Wilmad) were used. No H-decouplingwas employed due to sample heating which caused signal modification. Allspectra were corrected for background by the subtraction of a D₂ O blankspectrum. Tetrahedral and octahedral resonance line areas, obtained fromthe background-corrected spectra, were quantified by comparison to aseries of reprocessed spectra. These left-shifted reprocessed spectrawere obtained by sequentially removing 50, 100 and 150 μsec from theintensity vs. time FID (free induction decay) signal from each sample.This reprocessing separates broad field octahedral contributions fromthe less broad tetrahedral and octahedral signals in the resultingfrequency vs. time spectrum after Fourier transform of the modified FID.

The relative resonance line areas (as a percentage of total resonanceline areas) were obtained by dividing the integral curve height of aparticular resonance line by the sum of the integral curve heights ofall the resonance lines. This can be done, since the integral curve:heights are directly proportional to the resonance line areas. Forexample,: ##EQU1## where R_(A) is the percent of the total resonanceline areas occupied by resonance line A, I_(A) is the integral curveheight of resonance line A, and I_(i) is the integral curve height forthe ith resonance line. The percent area occupied by the 71.5-73.5resonance line, of the combined areas of the 62.5-63.5 ppm and 71.5-73.5ppm resonance line areas, is calculated as follows:

    R.sub.B =(I.sub.B /I.sub.c +I.sub.B)]×100

where R_(B) is the percentage of the combined areas of the 62.5-63.5 ppmand the 71.5-73.5 ppm resonance lines occupied by the 71.5-73.5 ppmresonance line area, I_(B) is the integral curve height of the 71.5-73.5ppm resonance line and I_(C) is the integral curve height of the62.5-63.5 ppm resonance line.

The present invention contemplates basic aluminum materials (that is,polymeric basic aluminum compounds) having the empirical formula:

    Al.sub.2 (OH).sub.6-a (X).sub.a,

where 0.5≦a≦5 and where X is a univalent complex oxoanion of nitrogen orhalogen having specified characteristics, characterized by:

(a) a peak 4 relative area of at least 25%, and a peak 3 relative areaof less than 60%, the sum of the relative peak 3 and peak 4 areas beingat least 50%;

(b) less than 10% chromatographic peaks eluting at shorter retentiontimes than peak 3, corresponding to peaks 1 and 2; (c) less than 25% ofthe aluminum in the form of Al^(b) polyhydroxyaquoaluminum;

(d) an ²⁷ Al NMR spectrum wherein 5%-30%, preferably 8%-18%, of thetotal area under the spectrum from 140 ppm to -80 ppm is contained in aresonance line at 71.5-73.5 ppm; and

(e) an ²⁷ Al NMR spectrum in which the area of the 71.5-73.5 ppmresonance line includes more than 50% of the combined areas of the62.5-63.5 ppm and 71.5-73.5 ppm resonance lines.

Moreover, the present invention ,contemplates methods of forming suchbasic aluminum materials, by reacting aluminum metal with an aluminumsalt to form the basic aluminum materials (which aluminum salt can beprepared in situ from aluminum metal and an inorganic acid.), whereinthe aluminum metal added is provided so as to achieve a low aluminummetal surface area in order to achieve the amount of aluminum in theform of Al^(b) polyhydroxyaquoaluminum, and the ²⁷ Al NMR spectrum, asset forth in the previous paragraph.

In addition, the present invention contemplates antiperspirantcompositions including such above-described basic aluminum material,another antiperspirant active material (e.g., a metal salt activeantiperspirant material) and optionally a neutral amino acid, andmethods of forming such compositions.

The present invention further contemplates forming basic aluminummaterials by reacting aluminum with the aluminum salt, in solution, withthe aluminum being added in stoichiometric or near-stoichiometricamounts (rather than adding the aluminum metal in large excess), so asto achieve the basic aluminum material having:

(1) for the ²⁷ Al NMR spectrum,

(a) a 71.5-73.5 ppm resonance line including at least 5% of the totalarea of the NMR spectrum, and up to and including 30% of the total area,preferably 8%-18% of the total area,

(b) a 0-5 ppm resonance line including at least 5% of the total NMRarea, and up to and including 30% of the total area, and

(c) a 62.5-63.5 ppm resonance line including less than 10% of the totalarea of the NMR spectrum;

(2) a size exclusion HPLC chromatogram which contains:

(a) a peak 4 relative area of at least 40%, a peak 3 relative area ofless than 30%, the sum of the relative peak 3 and peak 4 areas being atleast 50%,

(b) a combined peak 5 and peak 6 relative area of at least 15%, and

(c) less than 10% chromatographic peaks eluting at shorter retentiontimes than peak 3, corresponding to peaks 1 and 2; and

(3) less than 25% of the total aluminum in the form of Al^(b)polyhydroxyaquoaluminum.

As discussed previously, in one aspect of the invention described inU.S. patent application Ser. No. 07/233,008, filed Aug. 17, 1988, and inits continuation-in-part application filed May 2, 1990, a basic aluminummaterial is disclosed wherein at least 25% by weight of the basicaluminum material is in the form of Al^(b) polyhydroxyaquoaluminum. Ithas since been learned that this embodiment contains at least 5%, andusually less than 50%, of the total aluminum in the form of polymershaving a characteristic resonance line in the ²⁷ Al NMR spectrum. Thisline is 62.5-63.5 ppm downfield from the resonance line of Al³⁺ (6H₂ O).This line has been attributed to the presence of a complex ion [Al₁₃ O₄(OH)₂₄ (H₂ O)₁₂ ]⁷⁺ by Akitt, et al, in J.C.S. Dalton Transactions(1972), page 604. This complex ion is also known as an Al₁₃ -mer. ThisAl₁₃ -mer is associated with Al^(b) polyhydroxyaquoaluminum in thearticle by Fitzgerald, "Chemistry of Basic Commercial AluminumHydrolysis Complexes" in Laden, et al, Antiperspirants And Deodorants(1988), pages 225-227.

Furthermore, it has also been learned that the embodiment containing atleast 25% by weight of the basic aluminum material in the form of Al^(b)polyhydroxyaquoaluminum, in U.S. patent application Ser. No. 07/233,008,exhibits a characteristic resonance line in the ²⁷ Al NMR spectrum whichis 71.5-73.5 ppm downfield from the resonance line of Al³⁺ (6H₂ O). Thearea of the 71.5-73.5 ppm resonance line of the aforementioned basicaluminum material of No. 07/233,008 comprises between 0% and 50% of thecombined area of the 62.5-63.5 ppm and 71.5-73.5 ppm resonance lineareas. Surprisingly, however, an even further enhanced antiperspirantactivity is achieved by a basic aluminum material containingsignificantly less aluminum in the form of Al^(b)polyhydroxyaquoaluminum, and significantly less aluminum in the form ofpolymers characterized by an ²⁷ Al NMR resonance line at 62.5-63.5 ppmand significantly more aluminum in the form of polymers characterized bya ²⁷ Al NMR resonance line at 71.5-73.5 ppm.

As indicated previously, according to the present invention the aluminumadded to the aluminum salt in solution, to form the basic aluminummaterials, has a low aluminum metal surface area. While not limiting,such low aluminum metal surface area can be achieved in at least twoways, as follows:

(1) Aluminum metal of any shape or size, excluding ingots and includingpowder, but preferably between 0.005 inch and 0.1 inch (0.13 mm-2.5 mm)in diameter if spherical or 0.03 inch-0.25 inch (0.75 mm-6.4 mm) longoblong and 0.005 inch-0.05 inch (0.13 mm--1.3 mm) thick if not spherical(for example, small turnings), can be added to the vessel containing asolution of Al(Y^(w) O_(n))₃ at a molar ratio of aluminum metal toAl(Y^(w) O_(n))₃ which is between 0.5 and 2.5, to form the desired basicaluminum material Al₂ (OH)_(6-a) (Y^(z) O_(n))_(a), where a, z and n areas previously defined. This aluminum to Al(Y^(w) O_(n))₃ molar ratio of0.5-2.5 is considerably lower than the molar ratio of aluminum metal toaluminum halide used in the preparation of conventional basic aluminumhalides.

and/or

2. Aluminum metal can be added to the Al(Y^(w) O_(n))₃ solution inexcess of the aforementioned molar ratio of 2.5, provided that thealuminum metal is of sufficiently large particle size. In this aspect ofthe present invention, it is preferable not to use aluminum powder orsmall turnings as described previously (that is, small turnings 1/16inch to 1/8 inch long oblong pieces and 1/100 inch to 3/100 inch thick).Aluminum turnings, spheres, prills, shot, etc., nominally greater than0.1 inch (2.5 mm) in thickness, preferably between 0.1 inch and 0.4 inch(2.5 mm-10 mm) are examples of sufficiently large particle size for thealuminum metal.

Apart from the amount and/or size of the particles of aluminum utilizedin forming the basic aluminum material according to the presentinvention, the processing techniques are the same as described in U.S.patent application Ser. No. 07/233,008, filed Aug. 17, 1988 and thecontinuation-in-part application thereof filed May 2, 1990. In addition,apart from the basic aluminum material, the antiperspirant compositions,and methods of making such compositions, correspond to the compositionsand methods for forming the compositions as set forth in U.S. patentapplication Ser. No. 07/233,008, filed Aug. 17, 1988, and itscontinuation-in-part application filed May 2, 1990. The contents of eachof the U.S. patent applications Ser. No. 07/233,008, filed Aug. 17,1988, and the continuation-in-part application thereof filed May 2,1990, have been incorporated herein in their entirety by reference.

The materials and compositions of the present invention can beincorporated as a substitute for the active antiperspirant substance invarious conventional antiperspirant forms for axillary application, suchas aqueous and alcoholic solutions, solid sticks, roll-ons (suspensionsof dried active material, lotions, solutions, water-in-oil emulsions oroil-in-water emulsions), gels, creams, compressed powders, aerosols,etc. Attention is directed to U.S. Pat. No. 4,359,456, U.S. Pat. No.4,606,915 and British patent specification No. 1,568,831, for theirdisclosures of various components, utilized in antiperspirantcompositions, with which the material and composition of the presentinvention can be blended for forming antiperspirants for axillaryapplication. The materials and compositions of the present invention areused in antiperspirants in amounts equal to and greater than the amountsof conventional enhanced activity antiperspirant materials used inantiperspirants. For example, any emulsion (water-in-oil oroil-in-water) antiperspirant roll-on product can be prepared with 10-25%by weight of the materials and/or compositions of the present inventionwithout concern for the loss of enhanced antiperspirant activity.

Various specific examples of the present invention are set forth in thefollowing. Of course, such examples are illustrative and not limiting.In connection with the following examples are provided size exclusionchromatograms, and ²⁷ Al NMR diagrams, for products formed in suchexamples. Such chromatograms, and such ²⁷ Al NMR diagrams, were obtainedutilizing the analytical procedures discussed previously. The ferronresults are on a weight % basis of the basic aluminum material.

EXAMPLE 1

46.6 grams of aluminum nitrate nonahydrate are dissolved in deionizedwater to give 248.6 grams of total solution. The resultant 0.50Msolution is heated to 95° C. over a thirty minute period. 6.0 grams ofaluminum metal in the form of small turnings, approximately 1/16" to1/8" long oblong pieces, 1/100" to 3/100" thick, are added over a twominute period. Thus, a low molar ratio of aluminum metal to aluminumnitrate is used. A reaction temperature of 95°-99° C. is maintained withcontinuous stirring. After a total of 6 hours from the addition ofaluminum metal, the reaction mixture is quickly filtered hot to removeunreacted aluminum, if any. The solution is rapidly spray dried.Analytical analysis of the spray-dried powder indicates that it contains21.76% aluminum and 7.19% nitrogen. A 15% solution of this spray-driedpowder in deionized water is found to exhibit a pH of 3.84. A 10%solution contains 16.4% peak 3 area, 56.4% peak 4 area, a combined 18.1%peak 5 and peak 6 areas and no earlier chromatographic peaks, as shownin FIG. 1. The ferron reaction results in 10.4% Al^(a), 20.1% Al^(b) and69.5% Al^(c). The ²⁷ Al NMR of a 10% aqueous solution of the spray-driedpowder is shown in FIG. 4. As can be seen, the 71.5-73.5 ppm resonanceline area is 11% of the total NMR resonance line area, the 62.5-63.5 ppmresonance line area is 1% of the total resonance line area, the71.5-73.5 ppm resonance line area comprises 93% of the combined62.5-63.5 ppm and 71.5-73.5 ppm line areas, and the 0-5 ppm resonanceline area is 7.2% of the total resonance line area.

EXAMPLE 2

46.6 grams of aluminum nitrate nonahydrate are dissolved in deionizedwater to give 248.6 grams of total solution. The resultant 0.50Msolution is heated to 95° C. over a thirty minute period. 6.0 grams ofaluminum metal in the form of small turnings, approximately 1/16" to1/8" long oblong pieces, 1/100" to 3/100" thick, are added over a twominute period. Thus, a low molar ratio of aluminum metal to aluminumnitrate is used. A reaction temperature of 95°-99° C. is maintained withcontinuous stirring. After a total of 5 hours from the addition ofaluminum metal, the reaction mixture is quickly filtered hot to removeunreacted aluminum, if any. The solution is rapidly spray-dried.Analytical analysis of the spray-dried powder indicates that it contains20.52% aluminum and 7.87% nitrogen. A 15% solution of this spray-driedpowder in deionized water is found to exhibit a pH of 3.81. A 10%solution contains 14.9% peak 3 area, 50.7% peak 4 area, a combined 26.6%peak 5 and peak 6 areas and no earlier chromatographic peaks, as shownin FIG. 2. The ferron reaction results in 14.8% Al^(a), 22.0% Al^(b) and63.2% Al^(c). The ²⁷ Al NMR of a 10% aqueous solution of the spray-driedpowder is shown in FIG. 5. As can be seen, the 71.5-73.5 ppm resonanceline area is 11% of the total NMR resonance line area, the 62.5-63.5 ppmresonance line area is 1.4% of the total resonance line area, the71.5-73.5 ppm resonance line area comprises 88% of the combined62.5-63.5 ppm and 71.5-73.5 ppm line areas, and the 0-5 ppm resonanceline area is 9.6% of the total NMR resonance line area.

EXAMPLE 3

28.1 grams of aluminum nitrate nonahydrate are dissolved in deionizedwater to give 100.0 grams of total solution. The resultant 0.75Msolution is heated to 95° C. over a thirty minute period. 16.2 grams ofaluminum metal in the form of spherical-like shot, approximately 0.03"to 0.175" (0.76 mm-4.4 mm) in diameter, are added over a two minuteperiod. This example uses an excess of aluminum metal, having a largeshot size. A reaction temperature of 95°-99° C. is maintained withcontinuous stirring. After a total of 3.5 hours from the addition ofaluminum metal, the reaction mixture is quickly filtered hot to removeunreacted aluminum, if any. The solution is rapidly spray-dried.Analytical analysis of the spray-dried powder indicates that it contains22.16% aluminum and 6.73% nitrogen. A 15% solution of this spray-driedpowder in deionized water is found to exhibit a pH of 4.10. A 10%solution contains 24.4% peak 3 area, 59.9% peak 4 area, a combined 8.1%peak 5 and peak 6 areas and no earlier chromatographic peaks, as shownin FIG. 3. The ferron reaction results in 6.1% Al^(a), 24.9% Al^(b) and70.0% Al^(c). The ²⁷ Al NMR of a 10% aqueous solution of the spray-driedpowder is shown in FIG. 6. As can be seen, the 71.5-73.5 ppm resonanceline area is 12.4% of the total NMR resonance line area, the 62.5-63.5ppm resonance line area is 3.1% of the total resonance line area, the71.5-73.5 ppm resonance line area comprises 80% of the combined62.5-63.5 ppm and 71.5-73.5 ppm line areas, and the 0-5 ppm resonanceline area is 3.6% of the total NMR resonance line area.

EXAMPLE 4

69.9 grams of aluminum nitrate nonahydrate are dissolved in deionizedwater to give 248.4 grams of total solution. The resultant 0.75Msolution is heated to 85°-90° over a thirty minute period. 9.03 grams ofaluminum metal (the stoichiometric amount required), as small turnings,are added over two minutes. Thus, a low molar ratio of aluminum metal toaluminum nitrate is used. The reaction temperature is raised to 95°-100°C. and maintained at this temperature for at least 3 hours, or until allof the aluminum metal has dissolved. Peak 3 area remains below 10% ofthe total peak area even 7 hours post-aluminum metal addition. After 4hours post-aluminum metal addition, the resultant solution exhibits5.86% peak 3 area, 56.94% peak 4 area and no earlier chromatographicpeaks, as shown in FIG. 7. After 5 hours post-aluminum metal additionand at 95°-100° C., the solution exhibits 7.35% peak 3 area, 68.87% peak4 area and no earlier peaks, as shown in FIG. 8. After 6.5 hours, thesame solution exhibits 6.81% peak 3 area, 76.35% peak 4 area and noearlier chromatographic peaks as shown in FIG. 9. Thus, a long reactiontime is used. Isolation of solid can be accomplished by spray- orfreeze-drying.

COMPARATIVE EXAMPLE 1

Aluminum nitratohydrate was prepared according to a technique describedin application Ser. No. 07/233,008, filed Aug. 17, 1988. 349.5 grams ofaluminum nitrate nonahydrate are dissolved in 892.5 grams of deionizedwater. The resultant 0.75M solution is heated to 65°-70° C. withcontinuous stirring, and 250.9 grams of aluminum metal (small turnings,approximately 1/16" to 1/8" long oblong pieces, 1/100" to 1/300" thick),are added in excess over a five minute period. A reaction temperature of70°-95° C. is maintained with continuous stirring. After a total of 3.7hours from the addition of aluminum metal, the reaction mixture isfiltered hot to remove the unreacted aluminum metal. The resultantsolution contains 58.5% HPLC peak 4 relative area, 24.1% relative peak 3area, and no earlier chromatographic peaks. The solution is thenspray-dried. A 10% aqueous solution of the spray-dried powder contains57.4% peak 4 relative area, 27.8% peak 3 relative area and no earlierchromatographic peaks, as shown in FIG. 10. The ferron reaction resultsin 14.9% Al^(a), 44.1% Al^(b), and 41.0% Al^(c). The ²⁷ Al NMR of a 10%aqueous solution of the spray-dried powder is shown in FIG. 11. As canbe seen, the 71.5-73.5 ppm resonance line area is barely perceptible atless than 1% of the total NMR resonance line area, the 62.5-63.5 ppm NMRresonance line area is 8% of the total resonance line area, and the 0-5ppm resonance line area comprises 2% of the total NMR resonance linearea.

The basic aluminum material from. Example 3 and from Comparative Example1 were separately evaluated in two separate antiperspirant clinicalstudies at an independent testing laboratory. The two above-mentionedbasic aluminum materials were tested as spray-dried powders suspended ina non-aqueous base containing volatile silicone and stearyl alcohol. Theconcentration of the spray-dried powders in the base was 24%-25% byweight.

The clinical protocol for each study was identical. Approximately 45adult female subjects age 18 through 65 completed the studies. Eachsubject abstained from the use of all antiperspirants 17 days prior totreatment with the test materials. Test treatment was distributed astreatment pairs for application during the test period so that twodifferent treatments, on contralateral axillae, were randomized forright and left axillary assignments among the total number of subjects.Sweating of the subjects was induced by having the subjects sit in a"hot room" maintained at 100°±2° F. and at a relatively humidity ofabout 35%. During the first 40 minutes of sweat stimulation, thesubjects held unweighed Webril pads (nonwoven cotton padding fabric) intheir axillae. This preliminary warm-up period was followed by twosuccessive 20 minute collection periods, during which the subjects heldpreweighed Webril pads in their axillae. These Webril pads were weighedbefore and after each 20 minute collection. The amount of sweatcollected in each 20 minute period was used as an independentmeasurement of sweat output. Sweat output was obtained both prior totreatment with the test materials (to establish a pre-treatment baseline sweat output value) and 24 hours following the fourth treatment.Test material treatment consisted of 4 daily doses of 0.5 grams of theabove-mentioned formulation bases.

The data was analyzed using a general linear model in which thelogarithm of post-treatment sweat output was a dependent variable. Thelogarithm of base line sweat output was a covariate. A modification ofthe Wooding and Finkelstein crossover model was used. As can be seenfrom the data presented in Table 1, the basic aluminum material of thepresent invention is a significantly more effective antiperspirant thanthat in Comparative Example 1.

                  TABLE 1                                                         ______________________________________                                        Formulation                                                                             Pre-treatment                                                                             Post-treatment                                                                            %                                           Base      Sweat       Sweat       Sweat                                       Containing:                                                                             Output (mg) Output (mg) Reduction                                   ______________________________________                                        Example 3 1124        516         54.1                                        Comparative                                                                             1135        704         38.0                                        Example 1                                                                     ______________________________________                                    

A similar result was obtained when the basic aluminum material fromExample 2 and from Comparative Example 1 were evaluated in two separateantiperspirant clinical studies at the same independent testinglaboratory.

Accordingly, by the present invention an even further enhanced activityantiperspirant material is provided, which can be produced without thenecessity of using large aluminum metal surface areas or using excessaluminum (thereby decreasing costs for producing the material) and alsowithout the necessity of using powdered aluminum (and any possibleexplosion hazard due to use of such powder). Moreover, according to thepresent invention a composition including such basic aluminum materialand method of providing such composition, can easily be achieved.

While we have shown and described several embodiments in accordance withthe present invention, it is understood that the same is not limitedthereto, but is susceptible of numerous changes and modifications asknown to those skilled in the art. Therefore, we do not wish to belimited to the details shown and described herein, but intend to coverall such changes and modifications as are encompassed by the scope ofthe appended claims.

We claim:
 1. Antiperspirant compositions having the formula:

    [Al.sub.2 (OH).sub.6-a X.sub.a ].sub.w [DO.sub.p (OH).sub.m Q.sub.n ].sub.y [neutral amino acid].sub.z,

where 0.5≦a ≦5.0, X is a univalent complex oxoanion of nitrogen or ahalogen, which forms salts with Al³⁺ in aqueous dissociated, which isreadily soluble in water with metallic ions in the solution, and whichforms conjugate acids that are strong acids, w: y ranges from about0.3:1 to about 6.0:1, z:y ranges from 0 to 1.3:1, p is either 0 or 1,where when p is O m is O and n is 4, and when p is 1 then m+n is 2, D isa metal cation selected from the group consisting of Zr, Hf, Ti and Sn,and Q is a halide or X, Al₂ (OH)_(6-a) X_(a) further being characterizedby: (a) size exclusion high performance liquid chromatography peakscorresponding to peak 3 and peak 4 of the size exclusion chromatogramproduced from a high performance liquid chromatography technique; (b) apeak 4 relative area of at least 25%, and a peak 3 relative area of lessthan 60%, the sum of the relative peak 3 and peak 4 areas being at least50%; (c) less than 10% chromatographic peaks eluting at shorterretention times that peak 3, corresponding to peaks 1 and 2; (d) lessthan 25% of the aluminum being in the form of Al^(b)polyhydroxyaquoaluminum; (e) an ²⁷ Al NMR spectrum wherein 5%-30% of thetotal area under the spectrum from 140 ppm to -80 ppm is contained in aresonance line at 71.5-73.5 ppm; and (f) an ²⁷ Al NMR spectrum in whichthe area of the 71.5-73.5 ppm resonance line includes more than 50% ofthe combined areas of the 62.5-63.5 ppm and 71.5-73.5 ppm resonancelines.
 2. Antiperspirant compositions according to claim 1, wherein z:yis greater than O.
 3. Antiperspirant compositions according to claim 1,wherein the composition has a peak 4 area that is at least 25%, a peak 3area that is less than 50%, and the sum of the peak 3 and peak 4 areasof the composition is at least 40%.
 4. Antiperspirant compositionsaccording to claim 1, wherein 8%-18% of the total area under the ²⁷ Alspectrum from 140 ppm to -80 ppm is contained in a resonance line at71.5-73.5 ppm.
 5. An antiperspirant active composition, comprising:(1)at least one basic aluminum material having the empirical formula:

    Al.sub.2 (OH).sub.6-a X.sub.a,

where 0.5≦a ≦5.0; and X is a univalent complex oxoanion of nitrogen or aunivalent complex oxoanion of a halogen, which form salts with Al³⁺ inaqueous solution, so that these salts are essentially completelydissociated, which is readily soluble in water with metallic ions in thesolution, and which forms conjugate acids that are strong acids, the atleast one basic aluminum material being further characterized by: (a)size exclusion high performance liquid chromatography peakscorresponding to peak 3 and peak 4 of the size exclusion chromatogramproduced from a high performance liquid chromatography technique; (b) apeak 4 relative area of at least 25%, and a peak 3 relative area of lessthan 60%, the sum of the relative peak 3 and peak 4 areas being at least50%; (c) less than 10% chromatographic peaks eluting at shorterretention times than peak 3, corresponding to peaks 1 and 2; (d) lessthan 25% of the aluminum being in the form of Al^(b)polyhydroxyaquoaluminum; (e) an ²⁷ Al NMR spectrum wherein 5% to 30% ofthe total area under the spectrum from 140 ppm to -80 ppm is containedin a resonance line at 71.5-73.5 ppm; and (f) an ²⁷ Al NMR spectrum inwhich the area of the 71.5-73.5 ppm resonance line includes more than50% of the combined areas of the 62.5-63.5 ppm and 71.5-73.5 ppmresonance lines, (2) at least one other antiperspirant active material,which is selected from the group consisting of antiperspirant active Zrsalts, antiperspirant active Hf salts, antiperspirant active Ti saltsand antiperspirant active Sn salts, and (3) a neutral amino acid.
 6. Anantiperspirant active composition according to claim 5, having theformula:

    [Al.sub.2 (OH).sub.6-a X.sub.a ].sub.w [DO.sub.p (OH).sub.m Q.sub.n ].sub.y [neutral amino acid].sub.z,

where a and X are as defined previously, w:y ranges from about 0.3:1 toabout 6.0:1, z:y is greater than 0 and up to 1.3:1, p is either O or 1,when p is O m is O and n is 4, and when p is 1 then m+n is 2, D is ametal cation selected from the group consisting of Zr, Hf, Ti and Sn,and Q is a halide or X.
 7. An antiperspirant composition according toclaim 6, wherein the neutral amino acid is selected from the groupconsisting of glycine, alanine and phenylanine.
 8. An antiperspirantactive composition according to claim 7, wherein the neutral amino acidis glycine.
 9. An antiperspirant active composition according to claim5, wherein the composition has a peak 4 relative area of at least 25%and a peak 3 relative area of less than 50%, the sum of the peak 3 andpeak 4 relative areas being at least 40%.
 10. An antiperspirant activecomposition according to claim 9, wherein the composition contains up to35% peak 1 relative area, and less than 10% peak 2 relative area.
 11. Anantiperspirant active compositions according to claim 5, wherein 8-18%of the total area under the ²⁶ Al spectrum from 140 ppm to -80 ppm iscontained in a resonance line at 71.5-73.5 ppm.
 12. An antiperspirantactive composition according to claim 6, wherein 8-18% of the total areaunder the ²⁷ Al spectrum from 140 ppm to -80 ppm is contained in aresonance line at 71.5-73.5 ppm.
 13. An antiperspirant activecomposition according to claim 6, wherein the composition has a peak 4relative area of at least 25% and a peak 3 relative area of less than50%, the sum of the peak 3 and peak 4 relative areas being at least 40%.14. An antiperspirant active composition according to claim 13, whereinthe composition contains up to 35% peak 1 relative area, and less than10% peak 2 relative area.
 15. An antiperspirant active compositionaccording to claim 5, wherein the at least one other antiperspirantactive material has the formula:

    DO.sub.p (OH).sub.m Q.sub.n,

where p is either O or 1; when p=O then m=O and n=4, and when p=1 thenm+n=2; Q is a halide or X, X having previously been defined; and D is ametal cation selected from the group consisting of Zr, Hf, Ti and Sn.16. An antiperspirant active composition according to claim 15, whereina molar ratio of the at least one basic aluminum material to the atleast one other antiperspirant active material is 0.3:1 to 6.0:1.
 17. Anantiperspirant active composition according to claim 5, wherein the atleast one other antiperspirant active material is zirconylhydroxychloride.
 18. An antiperspirant active composition according toclaim 17, wherein a molar ratio of the at least one basic aluminummaterial to the at least one other antiperspirant active material is0.3:1 to 6.0:1.
 19. An antiperspirant active composition according toclaim 5, wherein a molar ratio of the at least one basic aluminummaterial to the at least one other antiperspirant active material is0.3:1 to 6.0:1.
 20. An antiperspirant active composition, formed by aprocess comprising:(A) providing at least one basic aluminum materialhaving the empirical formula:

    Al.sub.2 (OH).sub.6-a X.sub.a,

where 0.5≦a≦5.0; and X is a univalent complex oxoanion of nitrogen or aunivalent complex oxoanion of a halogen, which forms salts with Al³⁺ inaqueous solution, so that these salts are essentially completelydissociated, which is readily soluble in water with metallic ions in thesolution, and which forms conjugate acids that are strong acids, the atleast one basic aluminum material being further characterized by: (a)size exclusion high performance liquid chromatography peakscorresponding to peak 3 and peak 4 of the size exclusion chromatogramproduced from a high performance liquid chromatography technique; (b) apeak 4 relative area of at least 25%, and a peak 3 relative area of lessthan 60%, the sum of the relative peak 3 and peak 4 areas being at least50%; (c) less than 10% chromatographic peaks eluting at shorterretention times than peak 3, corresponding to peaks 1 and 2; (d) lessthan 25% of the aluminum being in the form of Al^(b)polyhydroxyaquoaluminum; (e) an ²⁷ Al NMR spectrum wherein 5% to 30% ofthe total area under the spectrum from 140 ppm to -80 ppm is containedin a resonance line at 71.5-73.5 ppm; and (f) an ²⁷ Al NMR spectrum inwhich the area of the 71.5-73.5 ppm resonance line includes more than50% of the combined areas of the 62.5-63.5 ppm and 71.5-73.5 ppmresonance lines, and (B) mixing said at least one basic aluminummaterial with (1) at least one other antiperspirant active material,which is selected from the group consisting of antiperspirant activesalts of Zr salts, antiperspirant active Hf salts, antiperspirant activeTi salts and antiperspirant active Sn salts, and (2) a neutral aminoacid.
 21. An antiperspirant active composition according to claim 20,wherein said at least one basic aluminum material is provided in anaqueous solution and is mixed with said at least one otherantiperspirant active material and said neutral amino acid in an aqueoussolution, to form a mixture in solution, the mixture in solution beingdried to form the antiperspirant active composition.
 22. Anantiperspirant active composition according to claim 21, wherein theantiperspirant active composition is in a powder form.
 23. Anantiperspirant active composition according to claim 21, wherein X isNO₃ ⁻.
 24. An antiperspirant active composition according to claim 20,wherein a molar ratio of the at least one basic aluminum material to theat least one other antiperspirant active material is 0.3:1 to 6.0:1. 25.An antiperspirant active composition according to claim 20, wherein theat least one other antiperspirant active material has the formula:

    DO.sub.p (OH).sub.m Q.sub.n,

where p is either O or 1; when p=O then m=O and n=4, and when p=1 thenm+n=2; Q is a halide or X, X having previously been defined; and D is ametal cation selected from the group consisting of Zr, Hf, Ti and Sn.26. An antiperspirant active composition according to claim 25, whereina molar ratio of the at least one basic aluminum material to the atleast one other antiperspirant active material is 0.3:1 to 6.0:1.
 27. Anantiperspirant active composition according to claim 20, wherein the atleast one other antiperspirant active material is zirconylhydroxychloride.
 28. An antiperspirant active composition according toclaim 27, wherein a molar ratio of the at least one basic aluminummaterial to the at least one other antiperspirant active material is0.3:1 to 6.0:1.
 29. A process of forming the antiperspirant activecomposition according to claim 5, comprising mixing said at least onebasic aluminum material, said at least one other antiperspirant activematerial and said neutral amino acid.
 30. The process according to claim29, wherein the at least one basic aluminum material and the at leastone other antiperspirant active material are in respective solutionswhen mixed.
 31. The process according to claim 29, wherein the mixing isperformed at room temperature.